In many types of retail, consumer, industrial and institutional applications, low-cost and yet high-quality paper-like displays are being demanded by users. Problems like the automation of manual labeling have presented a particularly difficult challenge to resolve. In commercial environments for example, advertising and merchandising electrical signage users desire wireless display systems capable of providing high image quality while enabling the formation and refreshing of images in a wireless manner.
The prior art in this wireless display field has typically incorporated radio frequency types of systems that require the use of discreet analogue components and rigid PC board assembly. Other prior art to be found in the field of electronic signage and low-cost wireless displays utilizes infrared systems. The lack of any significant market adoption of prior art paper-like display is directly related to higher cost, greater complexity in the electrochemical and physical properties of the electrophoretic and other paper-like systems and the implied higher costs related with RF and IR installations.
These problems have rendered electronic signage as the last area to be automated with a satisfactory technology in the supermarket and retail industries. For years shelf tags have failed to be automated due to the problems presented by high cost, complexity and lack of image quality. Users demand high image quality coupled with low cost of installation.
Due to the chosen system architecture by the prior art, both of these types of wireless systems RF and IR represent higher power and infrastructure costs. Because of the need for high volume of electronic paper-like displays for effective solution of pricing and merchandising needs, a new type of wireless paper-like display is needed. This innovation discloses an improvement over this prior art that enable users of breaking the lowest cost barrier for large volume penetration of the supermarket shelf edge and the automation of the paper label function in many different industries.
Some of the limitations of the prior art include: (1) high-cost of wireless communications hardware; (2) lower image quality; (3) unsuitability for large-surface products like road signs or billboards; (3) high power-consumption and (4) lack of a truly paper-white quality surface with similar characteristics to paper including high contrast and high quality colors that include the use of near perfect white as a paper-like background. Therefore, the present invention provides users with a low-cost paper-like display capable of wirelessly controlling the formation and refreshing of images on this new type of composite material for which we have coined the term “Optical Resonant Gel display.
Many electrophoretic displays have good qualities of brightness and contrast when compared with traditional LCD displays. Nevertheless, whenever these paper-like signs are employed in a wireless application that requires a low-cost per unit, this prior art has proven to be high in power consumption, i.e. requiring batteries and also high in cost due to the related hardware involved in the radio frequency or infrared wireless networking of these signs. In this field of prior art, one finds the use of rigid PC board designs that incorporate discreet analogue parts and mechanical plastic cases. In the field of electronic price tags, prior art designs typically use a plastic housing and a small LCD screen which fails to provide users with color or sufficient image quality for branding.
The purpose of this disclosure is to provide users with a new type of low-cost wireless electronic signage flexible paper-like display, capable of receiving wireless transmission of alphanumeric and visual images by means of optical communications. Images are formed and refreshed while pixels form and are erased by electrochemical methods, that include high contrast, exceptional brightness and wide viewing angles, in a wireless manner and at the lowest-possible cost. This optical system architecture permits the use of photovoltaic materials that not only provide a source for signal detection but also permit the constant recharging of a capacitor circuit in order to power the display.
This optical networking architecture also permits to reduce the part count and to digitize the signal directly from the photovoltaic receiver into the microprocessor, obviating the need for discreet analogue components for signal treatment or pre-amplification.
In addition, the use of an optical broadcasting architecture, permits the use of only four layers of composite materials instead of the traditional rigid PC board with many discreet integrated circuit analogue components. In the case of the present invention, the micro-controller processor provides all of the logic functions required both for signal detection, demodulation, decoding, error-correction and the ensuing display driver management.
Another area of innovation proposed by this invention, is the use of a simple electro-mechanical means for driving the formation of images on the display. This simple method utilizes ultra-thin copper wire X-Y array matrix in order to deliver small currents to the base of each electromechanical pixels. The functionality of the ORG display is provided by means of selectively switching matrices of X and Y coordinates, which in turn result in pixilation of alphanumeric and visual images on the surface of the display. Control for the pixel matrix is provided by a micro-controller processor (MCU) capable of driving a multiplexed array of pixel coordinates. The pixel matrix is originally loaded onto memory on-board the MCU and is then transmitted to the XY coordinates by means of a multiplexer component of the micro-controller which calculates the image and issues the necessary commands to switch DC current to the specified coordinate matrix.
Prior art display technology has largely failed to deliver the value to users due to high cost per unit, complex-retrofitting installations, and complicated integration with different software systems. In this field of use, hardware specific flaws like high power, rigid architecture, have directly contributed to a very low adoption rate.
Despite the fact that prior art innovations in electrophoretic encapsulation have led to better image quality, the problems related with wireless communications like RF and IR hardware and the ensuing large power consumption ratios have continued to be present. For many years different electrophoretic display technologies have sought and failed to gain market acceptance and widespread usage. In the case of the prior art, many electrophoretic displays use two-colored color capsules so as to provide a two-color capability for the display. However, since many of the capsules fail to align perfectly in orientation every time, the resolution and color of the surface is of lesser quality.
For example, the use of white and black sided capsules does not result in a pure black and white display, but instead results in a gray surface display due to the natural drift in orientation of many black or white elements. Therefore, the image quality is much lower than that of the present innovation, whereby the method of forming images is one where each pixel is perfectly coated with the surface gel until the moment when it becomes active by electrical current flowing through it.
Once pixels become active, they bulge upwards at the same time that the surface tension of the coating gel is dissolved, exposing the pixel element within the context of a perfectly even and smooth surrounding, formed by the uniform coating gel still semi-solid in the area adjacent to the perimeter. Therefore, image quality and color purity are enhanced and the use of pure black and white and color and white is enabled for display of alphanumeric and visual images.
In general, the resulting physical properties of the display surface are such that a highly uniform surface area is provided for contrast, brightness and resulting in high image quality. The present innovation provides for better control of light absorbency, optical properties, charge, mobility, shape, size, density, surface quality, surface stability and similarity with high quality print paper images. Many encapsulated electrophoretic displays typically may include two or more different types of particles located within the pixel color capsules.
Many of the particles may be of an anisotropic particles and a plurality of second particles also residing within the suspension fluid. Application of an electric current may first cause the anisotropic particles to assume a specific orientation and present a specific optical property. Application of a second electric field may then cause many of the second particles to translate, thereby disorienting the anisotropic particles and resulting in a distortion of the optical qualities of the display's surface.
Likewise, the orientation of the anisotropic particles may allow easier translation of the plurality of second particles, also resulting in a deterioration of the optical characteristics. Other types of prior art displays utilizing electro-chemical properties include the electro-osmotic displays. Such types of displays utilize capsules containing a refractive index matching that of the suspension fluid they are in, so as to permit for a more homogeneous surface upon application of an electric field. This method presents greater complications in terms of precise fulfillment of the chemical properties of the suspension fluid and the particles and leads to higher cost of manufacturing.
Therefore, it is desirable to provide an electro-chemical display capable of high quality optical characteristics while at the same time permit for a simplified manufacturing process and resulting lower cost.
Prior art techniques have included diverse types of materials for the creation of electrophoretic displays. These materials have experimented with different types of particles, dyes, suspending fluids and binders used in fabrication of the displays. In some cases the types of particles used include scattering pigments, absorbing pigments and luminescent particles. Such varied types of particles have included titania, which may be coated with a metal oxide or silicon oxide and have been constructed with a retro-reflective coating where microscopically each particle is similar to a cornered cube. Luminescent particles also may include zinc sulfide particles encapsulated with an insulating coating to reduce their electrical conduction and they are typically used in combination with another class of particles that is light absorbing like dyes.
The challenges posed by integrating diverse types of particles with complicated chemical and physical properties renders many of the proposed innovations in the prior art expensive and difficult to manufacture to such exacting parameters. The micro-coating techniques and elaborate combinations of electrophoretic particles required are expensive and result in slower manufacturing processes methods.